混合気中の湿度が燃焼におよぼす影響 : 第3報,エンジン出力などにおよぼす影響

抄録

It has been reported in many papers that the humidity in a mixture causes a lower S. I. engine output because of the decrease of combustion heat and flame speed. However, the reason for and the extent of the above-mentioned effect have not yet been elucidated. In order to clarify the effect of humidity on S. I. engine output, the author applied the relationship between the humidity and combustion period to the analytical model of an S. I. engine which formulates the work done on a piston as a function of ignition timing. The result shows that (1) humidity decreases S. I. engine output by about 4.5% at constant spark advance, but at optimum spark advance the reduction is about 1.2%, and (2) the rate of flame speed reduction as a result of humidity in a engine is the same as the rate in burner.